| Step | Hyp | Ref | Expression | 
						
							| 1 |  | eff | ⊢ exp : ℂ ⟶ ℂ | 
						
							| 2 | 1 | jctr | ⊢ ( 𝑆  ∈  { ℝ ,  ℂ }  →  ( 𝑆  ∈  { ℝ ,  ℂ }  ∧  exp : ℂ ⟶ ℂ ) ) | 
						
							| 3 |  | recnprss | ⊢ ( 𝑆  ∈  { ℝ ,  ℂ }  →  𝑆  ⊆  ℂ ) | 
						
							| 4 |  | dvef | ⊢ ( ℂ  D  exp )  =  exp | 
						
							| 5 | 4 | dmeqi | ⊢ dom  ( ℂ  D  exp )  =  dom  exp | 
						
							| 6 | 1 | fdmi | ⊢ dom  exp  =  ℂ | 
						
							| 7 | 5 6 | eqtri | ⊢ dom  ( ℂ  D  exp )  =  ℂ | 
						
							| 8 | 3 7 | sseqtrrdi | ⊢ ( 𝑆  ∈  { ℝ ,  ℂ }  →  𝑆  ⊆  dom  ( ℂ  D  exp ) ) | 
						
							| 9 |  | ssid | ⊢ ℂ  ⊆  ℂ | 
						
							| 10 | 8 9 | jctil | ⊢ ( 𝑆  ∈  { ℝ ,  ℂ }  →  ( ℂ  ⊆  ℂ  ∧  𝑆  ⊆  dom  ( ℂ  D  exp ) ) ) | 
						
							| 11 |  | dvres3 | ⊢ ( ( ( 𝑆  ∈  { ℝ ,  ℂ }  ∧  exp : ℂ ⟶ ℂ )  ∧  ( ℂ  ⊆  ℂ  ∧  𝑆  ⊆  dom  ( ℂ  D  exp ) ) )  →  ( 𝑆  D  ( exp  ↾  𝑆 ) )  =  ( ( ℂ  D  exp )  ↾  𝑆 ) ) | 
						
							| 12 | 2 10 11 | syl2anc | ⊢ ( 𝑆  ∈  { ℝ ,  ℂ }  →  ( 𝑆  D  ( exp  ↾  𝑆 ) )  =  ( ( ℂ  D  exp )  ↾  𝑆 ) ) | 
						
							| 13 | 4 | reseq1i | ⊢ ( ( ℂ  D  exp )  ↾  𝑆 )  =  ( exp  ↾  𝑆 ) | 
						
							| 14 | 12 13 | eqtrdi | ⊢ ( 𝑆  ∈  { ℝ ,  ℂ }  →  ( 𝑆  D  ( exp  ↾  𝑆 ) )  =  ( exp  ↾  𝑆 ) ) |